Attaching the CMUcam to the Vex controller

[foobert]

Originally Posted by skimoose

1. data connection - I planned to use the three wire RS-232 port on the camera out to the IFI TTL driver circuit just like on the full size FRC controller with a standard PWM cable. There is a schematic for the TTL driver at IFI here. The TTL drivers are available through IFI at $10 or you can build your own with components from Mouser, Digikey, or Jameco (sorry RadioShack doesn't stock the RS-232 driver chip) for about the same price. Modify two very short PWM cables. Tie the +5v (red) together from the Vex controller RX/TX ports and connect to the +5v (pin #4) on the TTL driver. Tie the two Gnd (black) together from the Vex controller RX/TX ports and connect to the Gnd (pin #1) on the TTL driver. Then take the signal (white) wires from the Vex controller RX/TX ports and connect to the TX and RX (pins #2 & 3) on the TTL driver respectively. Remember transmit from the camera would be receive on the controller and camera receive would be transmit on the Vex controller. Keep the TTL connection to the Vex controller very short. Use two sided foam tape to hold the TTL driver on the top of the Vex controller case.

is there a reason to not just use the programming cable? sure you've got to kludge a connector, but you've already blown $100 for an extra fancy level shifter, or did ifi obfuscate the functionality to the point that it won't work for plain old serial comms?